Defroster for an end of an ice forming tube



Sept. 24, 1957 M. S. CHAPMAN DEFROSTER FOR AN END OF AN ICE FORMING TUBEFiled April 1, 1955 INVENTOR N V v ATTORNEY United Merlin S. Chapman,Wheeling, W. Va. Application April 1, 1955, Serial No. 498,583 3 Claims.(Cl. 52107) The present invention relates to ice making machines and ismore particularly directed to such machines for producing tubes of ice.

In applicants co-pending application Serial No. 305,534, now Patent No.2,739,457, granted March 27, 1955, there is shown an ice making machineincluding a plurality of refrigerant receiving tubes for forming acoating of ice upon each tube. In order to thaw the surface of the icecoating at its area of contact with the tube upon which it has beenformed sufficiently to permit its sliding from the tube due to gravity,a hot refrigerant gas is introduced for slightly heating the icewhereupon the same slides as a tube downwardly to be broken up intosmall pieces by suitable members striking the same. Also shown in theaforementioned application, is a hollow plug mounted in each of saidtubes for receiving the hot refrigerant prior to the introduction of ahot gas into the tube for the purpose of initially freeing the lower endof the ice coating while all portions thereof remain frozen to the tube.In actual practice it has been found essential so to free the lowermostportion of the ice from the tube in order to insure that the coatingwill slide from the tube when the remainder of the tube is heatedsufliciently to free the remaining portion of the ice coating.

It is a principal object of the present invention to provide a defrosterfor the lower end of ice forming tubes which will readily free a portionof the ice formed around the ends of such tubes and yet which defrosteris not affected by the cooling refrigerant in or passing from saidtubes, nor does the defroster materially affect the temperature of thecooling refrigerant within such tubes.

Further objects of the invention will be in part obvious and in partpointed out in the following detailed description of the accompanyingdrawing in which:

Fig. 1 is a side elevation of an example of an ice mak ing machineincluding the present invention.

Fig. 2 is an enlarged detailed cross sectional view of the presentdefroster as mounted upon an ice forming tube.

Fig. 3 is a cross sectional view taken on line 3-3 of Fig. 2.

Fig. 4 is also a cross sectional view taken on line 44 of Fig. 2; and

Fig. 5 is an enlarged side elevation showing the present defrostermounted in the lower end of an ice forming Referring now moreparticularly to the accompanying drawings wherein like and correspondingparts are designated by similar reference characters, reference is madefirst of all to Fig. 1 which discloses an ice making machine, theoperation of which is more fully described in the aforementionedapplication Serial No. 305,534, new Patent No. 2,739,457, and which isincluded herein only as an example of a machine which can employ thepresent invention. Reference numeral 1 indicates the pipe leading from aconventional refrigerating apparatus for conveying a liquid refrigerantsuch as ammonia or the like to a tank 2. Liquid refrigerant renderedgaseous by absorptates P e T i 2 tion of heat in the process of freezingice is conveyed from said tank back to the low-pressure side of theaforementioned refrigerating apparatus by means of pipe 3. A controlvalve is indicated at 4 which connects tank 2 with a header 5 andcontrols the passage of the refrigerant fromsaid tank to said header. Aplurality of refrigerant receiving pipes or tubes 6 are connected tosaid header and extend substantially vertically downwardly therefrom.

A pipe 9 connected'to the exhaust or high-pressure end or side of therefrigerating apparatus compressor receives a hot compressed refrigerantfluid therefrom and conveys the same to a plurality of inlet pipes 10.An annular plate 11 has a pair of diametrically opposite and spacedapart openings 12 formed therethrough and said pipe 10 is connected tosaid plate at one of said openings. A circular plate 13 extendssubstantially vertical from the outer periphery of plate 11, while asecond plate 14 preferably formed oval in cross section extendssubstantially perpendicular from the inner edge of said plate 11. Asecond annular plate 15 extends between said plates 13 and 14substantially parallel to, but spaced above plate 11. These plates arewelded together at their points of contact with one another wherebyplate 11 forms the bottom, plates 13 and 14 the side walls and plate 15the top of an annular closed defroster casing.

Plate 13 extends above top 15 providing a circular flange 16 thereabove,which flange is to be connected by welding or the like to the lowerportion 17 of a tube 6. An annular plate 18 extends across the bore oftube 6 above the lower edge thereof with an opening 19, preferably ovatein form from which extends pipe 7 downwardly and exteriorly of tube 6.

By this arrangement, said defroster casing is spaced from plate 18providing an air space 20 therebetween. Also inner wall 14 of saidcasing is spaced from pipe 7 providing an air space 21 therebetween.

A plurality of pipes 22 are each connected to the other of said openings12'of each plate 11 and are also connected to a pipe 23 which in turn isconnected to pipe 24 which leads to the header 5 and through the by-passpipe 25 to valve casing 4.

A tube 26 of heat-insulating material surrounds pipe 7, pipe 8 andoutlet 8' as well as the section of pipe 8" beneath tubes 6 to preventthe formation of ice on said pipes and outlet during the presence ofliquid refrigerant therein which could freeze water received from thereabove. Pipe 8 is considerably larger than pipes 9 and 23 forming areservoir-like pipe whereby, when pipes 6 are filled with a hot gas, anyliquid that is formed in those tubes by the absorption of heat from icesleeves in freeing them' from the cold walls of tubes 6 will be carriedby gravity downward into reservoir pipes 8 and thus will not remain intubes 6 to delay thefreeing of the ice sleeves from the exterior wallsof those tubes.

In the operation of the present ice making machine, when valve -4 isopen discharging liquid refrigerant from tank 2 through header 5 intotubes 6, water is sprayed on said tubes and becomes frozen thereon dueto the absorption of the heat therein by the refrigerant. The

refrigerant in turn becomes heated, and partially turns to a gas whichpasses back to tank 2 through header 5 and thence is returnedthroughpipe 3 .to the low-pressure side of the system.

When a layer of ice of a desired thickness is formed on each of thetubes 6, the control valves for pipe 9 is opened admitting a hot gasfrom the high pressure side of the refrigerating system into pipe 9,thence through pipe 10 and into plugs 13, which are thereby heatedsufficiently to thaw the lower portion of the sleeves of ice to freesaid lower portion of said ice completely from plugs 13 and the lowerportion of the tubes 6, while these sleeves or cylinders of ice remainfrozen to the upper portions of the tubes 6. Said hot gas thence passesthrough pipe 22, pipe 23, pipe 24 and into the chamber 4 where it closesthe valve contained therein, thus preventing the reception into header 5and tubes 6 of any more liquid refrigerant' Said hot gas being underconsiderably higher pressure than the liquid refrigerant contained insaid header 5 and tubes'6, forces the same downwardly into pipe 8 andthence into pipes 8' and 8" and into the tank 2. When all liquidrefrigerant has been so exhausted from tubes 6, the valve in pipe 8" isclosed and the hot gas which has replaced the liquid refrigerant intubes 6 melts slightly the interior surfaces of the sleeves or cylindersof ice formed upon said tubes, so that they readily fall downwardly andare broken into convenient size in the method explained in applicantsco-pending application hereinbefore mentioned. The timing devicecontrolling the opening and closing of the valves in pipe 9 and pipe 8"is set to close the valve in pipe 9 and simultaneously open the valve inpipe 8" as soon as the harvesting of the sleeves or cylinders of icefrom the tubes 6 is completed. Ase soon as the valve in pipe 9 is closedand the valve in pipe 8" is opened, the pressures throughout the part ofthe system illustrated in the drawings above the valve in pipe 9equalize, whereupon the valve in cylinder 4 drops to its open positionspilling liquid refrigerant into header 5 and tubes 6 replacing the hotgas which flows upward through pipe 8 and also bubbles up through theliquid refrigerant through tubes 6, header 5 and into surge drum 2 andthence the hot gas is returned through pipe 3 to the low pressure sideof the system, and with the hot gas thus replaced in the tubes 6, theyare ready for the beginning of the next freezing cycle. The valve inpipe 8" may be allowed to remain open during the ice-forming or freezingcycle.

In Fig. 2 the lower end of the ice formed on a tube 6 is indicated at A.This ice forms on the periphery of tube 6 and also on the top portion ofthe outer wall 13 of the defroster only, as liquid refrigerant does notenter this defroster. Upon the introduction of the hot refrigerant gasthrough pipes 10, walls 13 are heated causing a slight melting of theice A on the periphery of said well and the heat likewise slightly meltsthe lower portion of the ice on tube 6, as hereinbefore described. Thus,the lower end of the ice tube is freed from these members and when thehot refrigerant thereafter passes into each of the tubes 6 from header5, it only requires a very slight melting of the ice to cause the sameto slide downwardly along and from said tubes.

Spaces 20 and 21, and insulator 26 which cover pipes 7 and 8, preventthe liquid refrigerant from tubes 6 from cooling the defroster and pipesand 22 which would reduce the efficiency of the hot refrigerant to beintroduced to the defroster. Similarly, the hot refrigerant in thedefroster does not heat the pipe 7 or plate 18 which would further heatthe refrigerant in said pipe and in tubes 6, and thereby prevents anincrease in the burden upon the refrigerant compressor and condenser.Accordingly, a highly efiicient ice making machine is provided whichquickly forms ice and discharges the same at a considerably greater ratethan generally provided by machines heretobefore known.

In order to effect an equal exhausting of the refrigerant from tubes 6into pipes 7 and 8, it has been found helpful to employ a Y-shapedoutlet 8 connected at two or more spaced-apart portions of the bottom ofsaid pipe 8, and leading to pipe 8". In this manner the refrigerant isequally withdrawn from all the tubes 6 substantially simultaneouslywhereupon the hot refrigerant will contact the entire surface of all ofthe tubes 6 at about the same time, and the ice will slide from alltubes at the same time and greatly facilitating the operation of themachine. Unless that construction be used, the refrigerant may remain insome of the tubes 6 until the ice has been freed from those which therefrigerant has been exhausted, hence delaying the harvesting of the icefrom those tubes 6 from which the exhaustion of the refrigerant has beendelayed. Pipe 8" is connected to tank 2 for returning the liquidrefrigerant thereto during the harvest cycle.

The present device for freeing the ice cylinders can readily be appliedto ice forming tubes of machines of types other than that shown herein,and accordingly, such changes to the present invention as come Withinthe scope of the appended claims is deemed to be a part of the presentinvention.

What I claim is:

1. A defroster for an end portion of a cylinder for forming'ice on theexterior periphery thereof comprising a pair of concentric spaced apartannular plates forming the side walls of the defroster casing, a ringshaped plate connecting and closing an end portion of said annularplates forming the top of said casing, a second and similar ring shapedplate connecting and closing the opposite end portion of said annularplates forming the bottom thereof, said second ring shaped plate havinga pair of spaced apart openings therethrough, a pair of pipes connectedto said second ring shaped plate each in communication with one of saidopenings for the passage of a heating medium to and from said casing andthe outer of said annular plates having a portion extending from saidfirst mentioned ring shaped plate for connection to the end of said iceforming cylinder positioning the top of said casing from and below saidcylinder providing an insulating air space therebetween.

2. An ice forming cylinder with defroster for ice making machinescomprising an elongated tube for receiving a refrigerant to form waterinto ice on the exterior periphery of said tube, an annular discextending completely across the lower bore of said tube, but spaced fromthe end thereof, a pipe connected to said disc in communication with theopening therein and extending from said tube for the discharge of saidrefrigerant, an annular casing surrounding said pipe and connected tothe end of said tube being positioned below and spaced from said discproviding an insulating air space therebetween and a plurality of spacedapart pipes connected to said casing in communication with the interiorthereof for conveying a heating medium to and from said casing todefrost an end portion of the ice formed on said tube and easing.

3. An ice forming cylinder with defroster for ice making machines asclaimed in claim 2, wherein a heat insulator is positioned between saidpipe connected to said disc and said casing and plurality of pipes forpreventing the formation of ice therebetween.

References Cited in the file of this patent UNITED STATES PATENTS170,508 Beath Nov. 30, 1875 2,080,639 Taylor May 18, 1937 2,397,347Gruner Mar. 26, 1946 2,595,588 Lee May 6, 1952? 2,618,129 Williams Nov.18, 1952 2,637,177 Reedall May 5, 1953 2,749,721 Trepaud June 12, 1956

